Program goals include the following projects, Regulation of Secondary Metabolite Production in Bioactive Species of Ceramiales (Rhodophyta) will determine which of the secondary metabolites found in extracts of these benthic red algae are responsible for their antibiotic activity. Ciguatera Toxins: Seasonality and Detection will examine factors determining observed seasonal variations in frequency of ciguatoxic fish and to design a test to detect poisonous fish prior to human consumption. Endothelial Intracellular, Membrane Bound and Secreted Sulfated Proteoglycans investigates sulfated proteoglycans produced by endothelial cell lines, determining the role of these proteoheparins in cell cytoskeletal structure and/or intracellular Ca++ sinks. Electrochemical Detection of Aflatoxins and Other Trichothecene Mycotoxins addresses the issue of detecting trace quantities of carcinogenic and renal toxins produced by fungi associated with cereal grains grown in tropical conditions. Interactions of Tetrapeptides Containing Aromatic Residues with Nucleic Acids will employ synthesized tetrapeptides as model systems for analyses of DNA binding properties, addressing specifically the nature of their interactions with single-, double-stranded and "damaged" DNA molecules. Hybrid Artificial Pancreas for Glucose Regulation evaluates the in vitro efficiency and durability of insulin release from rat pancreatic islets encapsulated in artificial capillary units and assesses the potential use of this technique in human beings. Reproductive Electrophysiology of the Rhesus Monkey seeks to systematically examine physiological measures of reproductive behavior, focusing on a better understanding of human anorgasmia and the role of female orgasm in fertilization. Physiology and Behavior of Adult Sex Change in Fish will delineate the temporal sequence of events in this process, and establish whether the behavioral cues that induce adult sex change also influence sexual differentiation in developing juveniles.